beaker-plugin-dat/lib/mime.js

Dat-protocol plugin for the Beaker browser

const through2 = require('through2')
const identify = require('identify-filetype')
const mime = require('mime')
const log = require('loglevel')

// config default mimetype
mime.default_type = 'text/plain'

exports.identifyStream = function (name, cb) {
  var first = true
  return through2(function (chunk, enc, cb2) {
    if (first) {
      first = false

      // try to identify the type by the chunk contents
      var mimeType
      var identifiedExt = identify(chunk)
      if (identifiedExt)
        mimeType = mime.lookup(identifiedExt)
      if (mimeType)
        log.debug('[DAT] Identified entry mimetype as', mimeType)
      else {
        // fallback to using the entry name
        mimeType = mime.lookup(name)
        log.debug('[DAT] Assumed mimetype from entry name', mimeType)
      }
      cb(mimeType)
    }
 
    this.push(chunk) 
    cb2()
  })
}